1. Field of the Invention
The present invention is generally related to wellhead components, and, more particularly, to a split locking ring for wellhead components.
2. Description of the Related Art
Oil and gas well typically comprise a number of different components that must be coupled together. For example, such components can include a casing head, a Christmas tree, a tubing head, a blowout preventer, etc. There are many known methods for securing one well component to another. For example, externally mounted clamping devices, that may be actuated either hydraulically or mechanically, are well known in the art. Such devices are usually relatively large, heavy and expensive.
There are other methods of connecting such components together. For example, as shown in FIG. 1, a first component 12 is coupled to a second component 14 via a flanged connection 15. More specifically, the flange 17 of the first component 12 and the flange 18 of the second component 14 are provided with openings 19 wherein a plurality of bolts or studs 20 and nuts are used to secure the first component 12 to the second component 14. The first component 12 is secured to a third component 16 via a single piece lock ring 22. The single piece lock ring 22 has an internal lip 26 that is adapted to engage a surface 27 of a flange 28 of the first component 12. The single piece lock ring 22 is threadingly coupled to the flange 32 of the third component 16 via a plurality of threads 30 (internal threads on the lock ring 22 and external threads on the flange 32). By threadingly coupling the single piece lock ring 22 to the flange 32, the first component 12 and second component 14 are securely coupled to one another.
One problem with the single piece lock ring 22 depicted in FIG. 1 is that it must be physically large enough in diameter to fit over the flanged connection 15, e.g., the upper flange 18 of the second component 14, or any other features of the components 12, 14 as the single piece lock ring 22 is installed. In general, this design constraint requires that the flange 28 on the first component 12 be large enough in diameter, i.e., oversized, such that the single piece lock ring 22 may be made large enough to be readily installed over the first and second components 12, 14. The requirement to make the single piece lock ring 22 large enough to be positioned over the first and second components 12, 14 can create various problems. More specifically, among other things, requiring the use of an oversized single piece lock ring 22 means that the various components, e.g., flanges 28, 32, are larger and heavier than would otherwise be required and thus more costly to manufacture and handle. Moreover, the requirement that the single piece lock ring 22 be of a relatively large size can be problematic in some applications in which there is limited space available, e.g., such as in a multiple completion well.
The present invention is directed to an apparatus and methods for solving, or at least reducing the effects of, some or all of the aforementioned problems.